SIST EN ISO 128-3:2020
(Main)Technical product documentation - General principles of representation - Part 3: Views, sections and cuts (ISO 128-3:2020)
Technical product documentation - General principles of representation - Part 3: Views, sections and cuts (ISO 128-3:2020)
This document specifies the general principles for presenting views, sections and cuts applicable to
various kinds of technical drawings (e.g. mechanical, electrical, architectural, civil engineering),
following the orthographic projection methods specified in ISO 5456-2. Views and sections for
shipbuilding technical drawings are discussed in ISO 128-15. Views and sections for 3D models are
discussed in ISO 16792.
Attention has also been given in this document to the requirements of reproduction, including
microcopying in accordance with ISO 6428.
Technische Produktdokumentation (TPD) - Allgemeine Grundlagen der Darstellung - Teil 3: Ansichten, Schnitte und Schnittansichten (ISO 128-3:2020)
Dieses Dokument legt die allgemeinen Grundlagen zur Darstellung von Ansichten, Schnitten und Schnittansichten fest, die für verschiedene Arten von technischen Zeichnungen gelten (z. B. Mechanik, Elektrik, Architektur, Tiefbau), wobei die in ISO 5456-2 festgelegten orthogonalen Projektionsmethoden befolgt werden. Ansichten und Schnitte in Zeichnungen des Schiffbaus sind Gegenstand von ISO 128-15. Ansichten und Schnitte in 3D-Modellen sind Gegenstand von ISO 16792.
Die Anforderungen an die Vervielfältigung, einschließlich Mikroverfilmung nach ISO 6428, wurden in diesem Dokument ebenfalls berücksichtigt.
Documentation technique de produits (TPD) - Principes généraux de représentation - Partie 3: Vues, sections et coupes (ISO 128-3:2020)
Le présent document établit les principes généraux de représentation des vues, des sections et des coupes applicables aux différents types de dessins techniques (par exemple génie mécanique, génie électrique, génie architectural, génie civil) suivant les méthodes de projection orthographique, spécifiées dans l'ISO 5456‑2. Les vues et sections pour les dessins techniques de construction navale sont discutées dans l'ISO 128‑15. Les vues et sections pour les modèles 3D sont discutées dans l'ISO 16792.
Les spécifications du présent document ont été établies en tenant compte des exigences de reproduction, y compris celles de la micrographie, conformément à l'ISO 6428.
Tehnična dokumentacija izdelkov - Splošna načela prikazovanja - 3. del: Pogledi, prerezi in odrezi (ISO 128-3:2020)
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
SIST EN ISO 128-3:2020
01-oktober-2020
Tehnična dokumentacija izdelkov - Splošna načela prikazovanja - 3. del: Pogledi,
prerezi in odrezi (ISO 128-3:2020)
Technical product documentation - General principles of representation - Part 3: Views,
sections and cuts (ISO 128-3:2020)
Technische Produktdokumentation (TPD) - Allgemeine Grundlagen der Darstellung - Teil
3: Ansichten, Schnitte und Schnittansichten (ISO 128-3:2020)
Documentation technique de produits (TPD) - Principes généraux de représentation -
Partie 3: Vues, sections et coupes (ISO 128-3:2020)
Ta slovenski standard je istoveten z: EN ISO 128-3:2020
ICS:
01.110 Tehnična dokumentacija za Technical product
izdelke documentation
SIST EN ISO 128-3:2020 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
---------------------- Page: 1 ----------------------
SIST EN ISO 128-3:2020
---------------------- Page: 2 ----------------------
SIST EN ISO 128-3:2020
EN ISO 128-3
EUROPEAN STANDARD
NORME EUROPÉENNE
July 2020
EUROPÄISCHE NORM
ICS 01.100.01
English Version
Technical product documentation - General principles of
representation - Part 3: Views, sections and cuts (ISO 128-
3:2020)
Documentation technique de produits (TPD) - Technische Produktdokumentation (TPD) - Allgemeine
Principes généraux de représentation - Partie 3: Vues, Grundlagen der Darstellung - Teil 3: Ansichten,
sections et coupes (ISO 128-3:2020) Schnitte und Schnittansichten (ISO 128-3:2020)
This European Standard was approved by CEN on 12 June 2020.
CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2020 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 128-3:2020 E
worldwide for CEN national Members.
---------------------- Page: 3 ----------------------
SIST EN ISO 128-3:2020
EN ISO 128-3:2020 (E)
Contents Page
European foreword . 3
2
---------------------- Page: 4 ----------------------
SIST EN ISO 128-3:2020
EN ISO 128-3:2020 (E)
European foreword
This document (EN ISO 128-3:2020) has been prepared by Technical Committee ISO/TC 10 "Technical
product documentation" in collaboration with Technical Committee CEN/SS F01 “Technical drawings”
the secretariat of which is held by CCMC.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by January 2021, and conflicting national standards shall
be withdrawn at the latest by January 2021.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland,
Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of
North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the
United Kingdom.
Endorsement notice
The text of ISO 128-3:2020 has been approved by CEN as EN ISO 128-3:2020 without any modification.
3
---------------------- Page: 5 ----------------------
SIST EN ISO 128-3:2020
---------------------- Page: 6 ----------------------
SIST EN ISO 128-3:2020
INTERNATIONAL ISO
STANDARD 128-3
First edition
2020-06
Technical product documentation
(TPD) — General principles of
representation —
Part 3:
Views, sections and cuts
Documentation technique de produits (TPD) — Principes généraux de
représentation —
Partie 3: Vues, sections et coupes
Reference number
ISO 128-3:2020(E)
©
ISO 2020
---------------------- Page: 7 ----------------------
SIST EN ISO 128-3:2020
ISO 128-3:2020(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2020
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting
on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address
below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Fax: +41 22 749 09 47
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO 2020 – All rights reserved
---------------------- Page: 8 ----------------------
SIST EN ISO 128-3:2020
ISO 128-3:2020(E)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Basic conventions for views . 2
4.1 General information on views. 2
4.2 Choice of views . 3
4.3 Partial views . 3
4.4 Simplified view of symmetrical parts . . 4
4.5 First angle projection method . 4
4.6 First angle projection method views . 4
4.7 First angle projection graphical symbol . 5
4.8 Third angle projection method . 5
4.9 Third angle projection method views . 5
4.10 Third angle projection graphical symbol . 6
4.11 Other projection methods . 6
4.12 Enlarged features . 6
5 Reference indication for views and enlarged features . 7
5.1 General . 7
5.2 Details of the reference indication . 7
5.3 Examples of indication . 8
6 General information on cuts and sections . 9
6.1 General . 9
6.2 Indication of cuts and sections . 9
6.2.1 Cutting plane . 9
6.2.2 Identification of the cutting plane. 9
6.2.3 Identification of the cuts and sections . 9
6.2.4 Reference indication for cuts and sections .10
6.3 Sections revolved in the relevant view .11
6.4 Cuts/sections of symmetrical parts .12
6.5 Local cuts/sections .12
7 Basic conventions for representing areas on cuts and sections.13
7.1 General information on cuts and sections .13
7.2 Hatching .13
7.3 Shading or toning .14
7.4 Extra-wide continuous outlines .15
7.5 Thin sections .15
7.6 Thin adjacent sections .15
7.7 Specific materials .16
Annex A (normative) Graphical symbols .17
Annex B (informative) Former practices .20
Annex C (normative) Views on mechanical engineering technical drawings .22
Annex D (normative) Sections on mechanical engineering technical drawings .34
Annex E (normative) Projection methods in building technical drawings .39
Annex F (normative) Representation of views, sections and cuts on construction drawings .41
Bibliography .48
© ISO 2020 – All rights reserved iii
---------------------- Page: 9 ----------------------
SIST EN ISO 128-3:2020
ISO 128-3:2020(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/ patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to the
World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see www .iso .org/
iso/ foreword .html.
This document was prepared by Technical Committee ISO/TC 10, Technical product documentation, in
collaboration with the European Committee for Standardization (CEN) Technical Committee CEN/SS
F01, Technical drawings, in accordance with the Agreement on technical cooperation between ISO and
CEN (Vienna Agreement).
This first edition cancels and replaces the following documents:
— ISO 128-30:2001
— ISO 128-33:2018
— ISO 128-34:2001
— ISO 128-40:2001
— ISO 128-44:2001
— ISO 128-50:2001
The main changes to these documents are as follows:
— harmonization of the former parts listed above;
— introduction of reference indication for views and enlarged features;
— use of arc arrow in special position of views moved to a former practice annex.
A list of all parts in the ISO 128 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www .iso .org/ members .html.
iv © ISO 2020 – All rights reserved
---------------------- Page: 10 ----------------------
SIST EN ISO 128-3:2020
ISO 128-3:2020(E)
Introduction
This document contains generally applicable rules for the presentation of views, sections and cuts in all
kinds of technical product documentation. The first angle projection method (formerly referred to as
method E) and the third angle projection method (formerly referred to as method A) are described in
more detail in ISO 5456-2.
All figures in this document, excluding Figure 1, Figure 6 and Figure 7, have been drawn in first-angle
projection method unless other methods are stated. It should be understood that third-angle projection
or other methods could have been used equally well without prejudice to the principles established.
The application of views, sections and cuts within drawings of special technical fields varies
considerably. Therefore, rules of application specific to technical fields are given in Annex A, B and C.
© ISO 2020 – All rights reserved v
---------------------- Page: 11 ----------------------
SIST EN ISO 128-3:2020
---------------------- Page: 12 ----------------------
SIST EN ISO 128-3:2020
INTERNATIONAL STANDARD ISO 128-3:2020(E)
Technical product documentation (TPD) — General
principles of representation —
Part 3:
Views, sections and cuts
1 Scope
This document specifies the general principles for presenting views, sections and cuts applicable to
various kinds of technical drawings (e.g. mechanical, electrical, architectural, civil engineering),
following the orthographic projection methods specified in ISO 5456-2. Views and sections for
shipbuilding technical drawings are discussed in ISO 128-15. Views and sections for 3D models are
discussed in ISO 16792.
Attention has also been given in this document to the requirements of reproduction, including
microcopying in accordance with ISO 6428.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
1)
ISO 128-2:— , Technical drawings — General principles of presentation — Part 2: Basic conventions for lines
ISO 129-1, Technical product documentation (TPD) — Presentation of dimensions and tolerances — Part 1:
General principles
ISO 3098-1, Technical product documentation — Lettering — Part 1: General requirements
ISO 5456-2, Technical drawings — Projection methods — Part 2: Orthographic representations
ISO 6428, Technical drawings — Requirements for microcopying
ISO 10209:2012, Technical product documentation — Vocabulary — Terms relating to technical drawings,
product definition and related documentation
ISO 15519-1, Specification for diagrams for process industry — Part 1: General rules
ISO 81714-1, Design of graphical symbols for use in the technical documentation of products — Part 1:
Basic rules
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 10209 and the following apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
1) Under preparation. Stage at the time of publication: ISO/FDIS 128-2:2020.
© ISO 2020 – All rights reserved 1
---------------------- Page: 13 ----------------------
SIST EN ISO 128-3:2020
ISO 128-3:2020(E)
3.1
cut
sectional view
section (3.2) showing, in addition, outlines beyond the cutting plane
Note 1 to entry: While “cut” is generally used in the construction field, “section” is generally used in the
mechanical engineering field, regardless of the definitions in 3.1 or 3.2.
[SOURCE: ISO 10209:2012, 3.11, modified — Note 1 to entry added.]
3.2
section
representation showing only the outlines of an object lying in one or more cutting planes
Note 1 to entry: While “cut” is generally used in the construction field, “section” is generally used in the
mechanical engineering field, regardless of the definitions in 3.1 or 3.2.
[SOURCE: ISO 10209:2012, 3.61, modified — Note 1 to entry added.]
3.3
technical drawing
drawing showing a technical installation, process or product with a view to clarifying its structure and
enabling its construction
Note 1 to entry: For the purpose of this document, the term “technical drawing” is interpreted in the broadest
possible sense, encompassing the total package of documentation specifying the product (work piece,
subassembly, assembly).
[SOURCE: ISO 5127:2017, 3.4.7.54, modified — Note 1 to entry added.]
4 Basic conventions for views
4.1 General information on views
The most informative view of an object shall be used as the principle view, taking into consideration, for
example, its functioning position, position of manufacturing or mounting.
Each view, with the exception of the front or principal figure (view, plan, principal figure), shall be
given clear identification with a capital letter, repeated near the reference arrow needed to indicate the
direction of viewing for the relevant view. Whatever the direction of viewing, the capital letter shall
always be positioned in normal relation to the direction of reading and be indicated either above or on
the right side of the reference arrow.
The reference arrow is defined in Annex A (for the former practice of arc arrow, see Annex B), as is the
lettering height of the identification.
The designated views may be located irrespective of the principal figure. The capital letters identifying
the referenced views shall be placed immediately above the relevant views (see Figure 1).
2 © ISO 2020 – All rights reserved
---------------------- Page: 14 ----------------------
SIST EN ISO 128-3:2020
ISO 128-3:2020(E)
Figure 1 — Identification of referenced views
For applying views and sections to mechanical engineering technical drawings, Annex C and Annex D
shall apply. For applying projection methods in building technical drawings, Annex E shall apply. For
applying views, sections and cuts to construction technical drawings, Annex F shall apply.
4.2 Choice of views
When views (including cuts and sections) are needed, these shall be selected according to the following
principles:
— limit the number of views (and cuts and sections) to the minimum necessary but sufficient to fully
delineate the object without ambiguity;
— avoid the need for hidden outlines and edges;
— avoid unnecessary repetition of a detail.
Views and sections for 3D models are given in ISO 16792.
4.3 Partial views
Features needing specific illustration, but not meriting a full view, can be illustrated using a partial view
limited by a continuous narrow line with zigzags of type 01.1 according to ISO 128-2:— (see Figure 2).
© ISO 2020 – All rights reserved 3
---------------------- Page: 15 ----------------------
SIST EN ISO 128-3:2020
ISO 128-3:2020(E)
Figure 2 — Partial view
4.4 Simplified view of symmetrical parts
To save time and space, symmetrical objects can be drawn as a fraction of the whole [see Figure 3 a), b)
and c)].
The line of symmetry is identified at each of its ends by two narrow short parallel lines drawn at right
angles to it [see Figure 3 a), b) and c)]. The graphical symbol for symmetry shall be drawn in accordance
with A.3.
a) Example 1 b) Example 2 c) Example 3
Figure 3 — Examples of simplified views of symmetrical parts
4.5 First angle projection method
The first angle projection method, if used, shall be in accordance with ISO 5456-2.
4.6 First angle projection method views
With reference to the front view, (a), the other views are arranged as follows (see Figure 4):
— the view from above, (b), is placed underneath;
— the view from below, (e), is placed above;
— the view from the left, (c), is placed on the right;
4 © ISO 2020 – All rights reserved
---------------------- Page: 16 ----------------------
SIST EN ISO 128-3:2020
ISO 128-3:2020(E)
— the view from the right, (d), is placed on the left;
— the view from the rear, (f), may be placed on the left or right, as convenient.
Figure 4 — First angle projection method
4.7 First angle projection graphical symbol
The graphical symbol for the first angle projection method is shown in Figure 5. The proportions and
dimensions of this graphical symbol are specified in ISO 5456-2.
Figure 5 — First angle projection graphical symbol
4.8 Third angle projection method
The third angle projection method, if used, shall be in accordance with ISO 5456-2.
4.9 Third angle projection method views
With reference to the front view, (a), the other views are arranged as follows (see Figure 6):
— the view from above, (b), is placed above;
— the view from below, (e), is placed underneath;
— the view from the left, (c), is placed on the left;
— the view from the right, (d), is placed on the right;
— the view from the rear, (f), may be placed on the left or right, as convenient.
© ISO 2020 – All rights reserved 5
---------------------- Page: 17 ----------------------
SIST EN ISO 128-3:2020
ISO 128-3:2020(E)
Figure 6 — Third angle projection method
4.10 Third angle projection graphical symbol
The graphical symbol for the third angle projection method is shown in Figure 7. The proportions and
dimensions of this graphical symbol are specified in ISO 5456-2.
Figure 7 — Third angle projection graphical symbol
4.11 Other projection methods
Refer to ISO 5456-2 for information on other projection methods such as mirrored orthographic
projections.
4.12 Enlarged features
When the scale of a technical drawing does not allow all features to be clearly shown or dimensioned,
the unclear features shall be enclosed or encircled by a continuous narrow line (type 01.1), with the area
thus enclosed identified by a capital letter. The features in the area shall also be shown on an enlarged
scale, in a view that is broken with a continuous narrow freehand/free formed curve line (type 01.1).
This shall be accompanied by the identification letter and an indication of the scale beside it between
parentheses, as shown in Figure 8. The rules for lettering height are discussed in Annex A.
Figure 8 — Enlarged features
6 © ISO 2020 – All rights reserved
---------------------- Page: 18 ----------------------
SIST EN ISO 128-3:2020
ISO 128-3:2020(E)
For unambiguous relation between the circle and the identification letter, a leader line by a continuous
narrow line (type 01.1) and a reference line by a continuous narrow line (type 01.1) should be drawn.
See Figure 9.
Figure 9 — Enlarged features with leader line
5 Reference indication for views and enlarged features
5.1 General
On large-format mechanical technical drawings and technical drawings consisting of more than one
drawing sheet with an extensive amount of views and enlarged features, the readability should be
improved by information (reference indication) after the identification letter of the views.
The purpose is to find the views and the identification letters more easily on the technical drawing or
drawings.
On construction drawings, designations for views and enlarged features can be complemented by
general reference to other drawings containing the views/features.
5.2 Details of the reference indication
The reference indication after the identification letter on the views shall be in accordance with
ISO 15519-1.
Examples with explanation are shown in Figure 10 and Figure 11.
Figure 10 — Details of the reference indication with a single drawing
© ISO 2020 – All rights reserved 7
---------------------- Page: 19 ----------------------
SIST EN ISO 128-3:2020
ISO 128-3:2020(E)
Figure 11 — Details of the reference indication with multiple drawings
5.3 Examples of indication
Examples of indication are given in Table 1.
Table 1 — Examples of indication
Indication on technical dra
...
SLOVENSKI STANDARD
oSIST prEN ISO 128-3:2019
01-oktober-2019
Tehnična dokumentacija izdelkov - Splošna načela prikazovanja - 3. del: Pogledi,
prerezi in odrezi (ISO/DIS 128-3:2019)
Technical product documentation - General principles of representation - Part 3: Views,
sections and cuts (ISO/DIS 128-3:2019)
Technische Produktdokumentation (TPD) - Allgemeine Grundlagen der Darstellung - Teil
3: Ansichten, Schnitte und Schnittansichten (ISO/DIS 128-3:2019)
Documentation technique de produits (TPD) - Principes généraux de représentation -
Partie 3: Vues, sections et coupes (ISO/DIS 128-3:2019)
Ta slovenski standard je istoveten z: prEN ISO 128-3
ICS:
01.110 Tehnična dokumentacija za Technical product
izdelke documentation
oSIST prEN ISO 128-3:2019 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
---------------------- Page: 1 ----------------------
oSIST prEN ISO 128-3:2019
---------------------- Page: 2 ----------------------
oSIST prEN ISO 128-3:2019
DRAFT INTERNATIONAL STANDARD
ISO/DIS 128-3
ISO/TC 10 Secretariat: SIS
Voting begins on: Voting terminates on:
2019-08-19 2019-11-11
Technical product documentation — General principles of
representation —
Part 3:
Views, sections and cuts
Documentation technique de produits (TPD) — Principes généraux de représentation —
Partie 3: Vues, sections et coupes
ICS: 01.100.01
THIS DOCUMENT IS A DRAFT CIRCULATED
This document is circulated as received from the committee secretariat.
FOR COMMENT AND APPROVAL. IT IS
THEREFORE SUBJECT TO CHANGE AND MAY
NOT BE REFERRED TO AS AN INTERNATIONAL
STANDARD UNTIL PUBLISHED AS SUCH.
IN ADDITION TO THEIR EVALUATION AS
ISO/CEN PARALLEL PROCESSING
BEING ACCEPTABLE FOR INDUSTRIAL,
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
STANDARDS MAY ON OCCASION HAVE TO
BE CONSIDERED IN THE LIGHT OF THEIR
POTENTIAL TO BECOME STANDARDS TO
WHICH REFERENCE MAY BE MADE IN
Reference number
NATIONAL REGULATIONS.
ISO/DIS 128-3:2019(E)
RECIPIENTS OF THIS DRAFT ARE INVITED
TO SUBMIT, WITH THEIR COMMENTS,
NOTIFICATION OF ANY RELEVANT PATENT
RIGHTS OF WHICH THEY ARE AWARE AND TO
©
PROVIDE SUPPORTING DOCUMENTATION. ISO 2019
---------------------- Page: 3 ----------------------
oSIST prEN ISO 128-3:2019
ISO 128-3:2019(E)
ISO/DIS 128-3:2019(E)
Contents
Foreword . iv
Introduction. vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions. 2
4 Basic conventions for views . 2
5 Reference indication for views and enlarged features . 7
6 General information on cuts and sections . 9
7 Basic conventions for representing areas on cuts and sections . 13
Annex A (Normative) Graphical symbols . 17
Annex B (informative) Former practices . 19
Annex C (Normative) Views on mechanical engineering technical drawings . 21
Annex D (Normative) Sections on mechanical engineering technical drawings . 33
Annex E (Normative) Projection methods in building technical drawings . 38
Annex F (Normative) Technical drawings - Construction drawings - Representation of
views, sections and cuts . 40
Bibliography . 48
COPYRIGHT PROTECTED DOCUMENT
© ISO 2019
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting
on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address
below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Fax: +41 22 749 09 47
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
̹ ʹͲͳͻ–ŽŽ”‹‰Š–•”‡•‡”˜‡† ‹‹‹
ii © ISO 2019 – All rights reserved
---------------------- Page: 4 ----------------------
oSIST prEN ISO 128-3:2019
ISO 128-3:2019(E)
Contents
Foreword . iv
Introduction. vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions. 2
4 Basic conventions for views . 2
5 Reference indication for views and enlarged features . 7
6 General information on cuts and sections . 9
7 Basic conventions for representing areas on cuts and sections . 13
Annex A (Normative) Graphical symbols . 17
Annex B (informative) Former practices . 19
Annex C (Normative) Views on mechanical engineering technical drawings . 21
Annex D (Normative) Sections on mechanical engineering technical drawings . 33
Annex E (Normative) Projection methods in building technical drawings . 38
Annex F (Normative) Technical drawings - Construction drawings - Representation of
views, sections and cuts . 40
Bibliography . 48
© ISO 2019 – All rights reserved iii
---------------------- Page: 5 ----------------------
oSIST prEN ISO 128-3:2019
ISO 128-3:2019(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO
collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of any
patent rights identified during the development of the document will be in the Introduction and/or on
the ISO list of patent declarations received (see www.iso.org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation on the meaning of ISO specific terms and expressions related to conformity
assessment, as well as information about ISO's adherence to the World Trade Organization (WTO)
principles in the Technical Barriers to Trade (TBT) see the following URL:
www.iso.org/iso/foreword.html.
The committee responsible for this document is Technical Committee ISO/TC 10, Technical product
documentation.
This standard combines 6 related former ISO standard parts into a new standard (ISO 128-3).
ISO 128-3 under the general title: General principles of representation Part 3: Views, Sections and Cuts,
consists of the following former ISO 128 parts:
— Former Part 30: Basic conventions for views
— Former Part 40: Basic conventions for cuts and sections
— Former Part 50: Basic conventions for representing areas on cuts and sections
ISO 128- 3 —Annex A: consists of:
— Former ISO 128 Part 30: Basic conventions for views – Annex A - Graphic symbols
— Former ISO 128 Part 40: Basic conventions for cuts and sections - Annex A - Graphic symbols
ISO 128- 3 —Annex B: consists of
— Former practices from former ISO 128-30 and ISO 128-40
ISO 128- 3 —Annex C: consists of:
— Former ISO 128 Part 34: Views on mechanical engineering drawings
iv © ISO 2019 – All rights reserved
---------------------- Page: 6 ----------------------
oSIST prEN ISO 128-3:2019
ISO 128-3:2019(E)
ISO 128- 3 —Annex D: consists of:
— Former ISO 128 Part 44: Sections on mechanical engineering drawings
ISO 128- 3 —Annex E: consists of:
— Former ISO 128 Part 43: Projection methods in building drawings
ISO 128- 3 —Annex F: consists of:
— Former ISO 128-33: Construction drawings – Representations of views, sections and cuts
A list of all parts in the ISO 128 series can be found on the ISO website.
© ISO 2019 – All rights reserved v
---------------------- Page: 7 ----------------------
oSIST prEN ISO 128-3:2019
ISO 128-3:2019(E)
Introduction
ISO 128-3 contains generally applicable rules for the presentation of views, sections and cuts in all kinds
of technical product documentation. The first angle projection method (formerly referred to as method
E) and the third angle projection method (formerly referred to as method A) are described in more detail
in ISO 5456-2
The application of views, sections and cuts within drawings of special technical fields varies considerably.
Therefore, rules of application specific to technical fields are given in annex A, B and C of ISO 128-3.
vi © ISO 2019 – All rights reserved
---------------------- Page: 8 ----------------------
oSIST prEN ISO 128-3:2019
ISO 128-3:2019(E)
Technical product documentation — General principles of
presentation — Part 3: Views, sections and cuts
1 Scope
This part of ISO 128 specifies the general principles for presenting views, cuts and sections applicable to
various kinds of technical drawings (mechanical, electrical, architectural, civil engineering, etc.),
following the orthographic projection methods specified in ISO 5456-2. Views and sections for
shipbuilding technical drawings are discussed in ISO 128-15. Views and sections for 3D models are
discussed in ISO 16792
For the purpose of this International Standard the term “technical drawing” shall be interpreted in the
broadest possible sense encompassing the total package of documentation specifying the product
(workpiece, subassembly, assembly).
Attention has also been given in this part of ISO 128 to the requirements of reproduction, including
microcopying in accordance with ISO 6428.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 128-2, Technical drawings — General principles of presentation — Part 2: Basic conventions for lines
ISO 129-1, Technical drawings — Indication of dimensions and tolerances — Part 1: General requirements.
ISO 3098-1, Technical product documentation — Lettering — Part 1: General requirements
ISO 5456-2, Technical drawings — Projection methods — Part 2: Orthographic representations
ISO 6428, Technical drawings — Requirements for microcopying
ISO 10209, Technical product documentation — Vocabulary — Terms relating to technical drawings,
product definition and related documentation
ISO 81714-1, Design of graphical symbols for use in the technical documentation of products — Part 1: Basic
rules
© ISO 2019 – All rights reserved 1
---------------------- Page: 9 ----------------------
oSIST prEN ISO 128-3:2019
ISO 128-3:2019(E)
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 10209 and the following apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at http://www.iso.org/obp
— IEC Electropedia: available at http://www.electropedia.org/
3.1
cut
sectional view
section showing, in addition, outlines beyond the cutting plane
[SOURCE: ISO 10209:2012, 3.11]
Note 1 to entry: The usage of the terms “cut” and “section” differs between the mechanical engineering
and construction fields. While “cut” is generally used in the construction field, “section” is generally used
in the mechanical engineering field, regardless of the definitions in 3.1 or 3.2.
3.2
section
representation showing only the outlines of an object lying in one or more cutting planes
[SOURCE: ISO 10209:2012, 3.61]
Note 1 to entry: The usage of the terms “cut” and “section” differs between the mechanical engineering
and construction fields. While “cut” is generally used in the construction field, “section” is generally used
in the mechanical engineering field, regardless of the definitions in 3.1 or 3.2.
3.3
technical drawing
drawing showing a technical installation, process, or product with a view to clarifying their structure and
to enable for their construction
[SOURCE: ISO 5127:2017,3.4.7.54]
Note 1 to entry: For the purpose of this International Standard, the term “technical drawing” shall be
interpreted in the broadest possible sense, encompassing the total package of documentation specifying
the product (work piece, subassembly, assembly).
4 Basic conventions for views
4.1 General information on views
The most informative view of an object shall be used as the front or principal figure, taking into
consideration, for example, its functioning position, position of manufacturing or mounting.
Each view, with the exception of the front or principal figure (view, plan, principal figure), shall be given
clear identification with a capital letter, repeated near the reference arrow needed to indicate the
direction of viewing for the relevant view. Whatever the direction of viewing, the capital letter shall
always be positioned in normal relation to the direction of reading and be indicated either above or on
the right side of the reference arrow.
2 © ISO 2019 – All rights reserved
---------------------- Page: 10 ----------------------
oSIST prEN ISO 128-3:2019
ISO 128-3:2019(E)
The reference arrow is defined in Annex A (for the former practice of arc arrow, see Annex B), as is the
lettering height of the identification.
The designated views may be located irrespective of the principal figure. The capital letters identifying
the referenced views shall be placed immediately above the relevant views (see Figure 1).
Figure 1 — Identification of referenced views
4.2 Choice of views
When views (including cuts and sections) are needed, these shall be selected according to the following
principles:
— limit the number of views (and cuts and sections) to the minimum necessary but sufficient to
fully delineate the object without ambiguity;
— avoid the need for hidden outlines and edges;
— avoid unnecessary repetition of a detail.
Views and sections for 3D models are given in ISO 16792.
4.3 Partial views
Features needing specific illustration, but not meriting a full view, may be illustrated using a partial view
limited by a continuous narrow line with zigzags of type 01.1.19 according to ISO 128-2 (see Figure 2).
© ISO 2019 – All rights reserved 3
---------------------- Page: 11 ----------------------
oSIST prEN ISO 128-3:2019
ISO 128-3:2019(E)
Figure 2 — Partial view
4.4 Simplified view of symmetrical parts
To save time and space, symmetrical objects may be drawn as a fraction of the whole [see Figure 3 a), b)
and c)].
The line of symmetry is identified at each of its ends by two narrow short parallel lines drawn at right
angles to it [see Figure 3 a), b) and c)]. The graphical symbol for symmetry shall be drawn in accordance
with clause A.3 in Annex A.
a) Example 1 b) Example 2 c) Example 3
Figure 3 — Simplified view of symmetrical parts
4.5 First angle projection method
The first angle projection method is to be regarded as a requirement of this part of ISO 128. A more
detailed description of the first angle projection method is to be found in ISO 5456-2.
4 © ISO 2019 – All rights reserved
---------------------- Page: 12 ----------------------
oSIST prEN ISO 128-3:2019
ISO 128-3:2019(E)
4.6 First angle projection method views
With reference to the front view, (a), the other views are arranged as follows (see Figure 6):
— the view from above, (b), is placed underneath;
— the view from below, (e), is placed above;
— the view from the left, (c), is placed on the right;
— the view from the right, (d), is placed on the left;
— the view from the rear, (f), may be placed on the left or right, as convenient.
Figure 4 — First angle projection method
4.7 First angle projection graphical symbol
The graphical symbol for the first angle projection method is shown in Figure 5. The proportions and
dimensions of this graphical symbol are specified in ISO 5456-2.
Figure 5 —First angle projection graphical symbol
4.8 Third angle projection method
The third angle projection method is to be regarded as a requirement of this part of ISO 128. A more
detailed description of the third angle projection method is to be found in ISO 5456-2.
© ISO 2019 – All rights reserved 5
---------------------- Page: 13 ----------------------
oSIST prEN ISO 128-3:2019
ISO 128-3:2019(E)
4.9 Third angle projection method views
With reference to the front view, (a), the other views are arranged as follows (see Figure 6):
— the view from above, (b), is placed above;
— the view from below, (e), is placed underneath;
— the view from the left, (c), is placed on the left;
— the view from the right, (d), is placed on the right;
— the view from the rear, (f), may be placed on the left or right, as convenient.
Figure 6 — Third angle projection method
4.10 Third angle projection graphical symbol
The graphical symbol for the third angle projection method is shown in Figure 7. The proportions and
dimensions of this graphical symbol are specified in ISO 5456-2.
Figure 7 — Third angle projection graphical symbol
4.11 Other Projection Methods
Refer to ISO 5456-2 for information on other projection methods such as mirrored orthographic
projections
4.12 Enlarged features
When the scale of a technical drawing does not allow all features to be clearly shown or dimensioned, the
unclear features shall be enclosed or encircled by a continuous narrow line (type 01.1), with the area thus
6 © ISO 2019 – All rights reserved
---------------------- Page: 14 ----------------------
oSIST prEN ISO 128-3:2019
ISO 128-3:2019(E)
enclosed identified by a capital letter. The features in the area shall also be shown on an enlarged scale,
accompanied by the identification letter and an indication of the scale beside it between parentheses, as
shown in Figure 8
Figure 8 – Enlarged features
For unambiguous relation between the circle and the identification letter, a leader line by a continuous
narrow line (type 01.1) and a reference line by a continuous narrow line (type 01.1) should be drawn.
See figure 9.
Figure 9 – Enlarged features with leader line
5 Reference indication for views and enlarged features
5.1 General
On large-format technical drawings and technical drawings consisting of more than one drawing sheet
with an extensive amount of views and enlarged features, the readability should be improved by
information (reference Indication) after the identification letter of the views.
The purpose is to find the views and the identification letters more easily on the technical drawing or
drawings.
5.2 Details of the reference indication
The reference indication after the identification letter on the views identifies the following:
• The page/ sheet number of multiple-page technical drawings
• The grid coordinates (Plan square) according to the “ISO 5457 reference grid”.
The full notation shall consist of the items given in Figure 10.
© ISO 2019 – All rights reserved 7
---------------------- Page: 15 ----------------------
oSIST prEN ISO 128-3:2019
ISO 128-3:2019(E)
Figure 10 — Details of the reference indication
5.3 Examples of indication
Examples of indication is given in Table 1.
Table 1
Indication on technical drawing Interpretation
View A is represented at technical drawing
coordinates C10.
The identification letter and reference arrow on
the main view is represented at technical drawing
coordinates A3.
Enlarged feature Z is represented at technical
drawing coordinates D5
The indication of the enlarged feature Z is
represented at technical drawing coordinates B3
8 © ISO 2019 – All rights reserved
---------------------- Page: 16 ----------------------
oSIST prEN ISO 128-3:2019
ISO 128-3:2019(E)
6 General information on cuts and sections
6.1 General
The general rules for the arrangement of views apply equally when drawing cuts and sections.
6.2 Indication of cuts and sections
6.2.1 Cutting plane
The position of the cutting plane(s) shall be indicated by means of a long-dashed dotted wide line (cutting
line) of the type 04.2 according to ISO 128-2, Annex E or 04.2.1 according to ISO 128-2, Annex G. A straight
cutting plane shall be drawn to a suitable length for legibility (see Figure 11).
If the cutting plane changes its direction, the cutting line should only be drawn at the ends of the cutting
plane, where the cutting plane changes direction (see Figure 12).
The cutting line may be drawn to its full length (with a long-dashed dotted narrow line of the type 04.1
according to ISO 128-2, Annex D or 04.1 according to ISO 128-2, Annex F) if necessary for its legibility.
The direction of viewing for the relevant cut and section is indicated by the reference arrows (drawn with
a continuous wide line of type 01.2.8 according to ISO 128-2, Annex D or 01.2.8 according to ISO 128-2,
Annex F indicating the direction of viewing for the relevant cut and section, at the ends of the cutting line
(see Annex A).
The designated cut and section may be located irrespective of the view in which the cutting plane is taken.
Representation of areas on cuts and sections is covered in Clause 7.
6.2.2 Identification of the cutting plane
Each cut and section plane shall be given clear identification with twice the same capital letter, once at
each of the reference arrows. This identification should be positioned for reading from the bottom of the
technical drawing.
The 30° or 90° cut and section arrow is defined in Clause A.4, as is the lettering height of the identification.
6.2.3 Identification of the cuts and sections
The identification of the referenced cuts and sections shall be placed immediately above the relevant
representation. (see Figure 11 and 12)
© ISO 2019 – All rights reserved 9
---------------------- Page: 17 ----------------------
oSIST prEN ISO 128-3:2019
ISO 128-3:2019(E)
Figure 11 — Example from construction field
Figure 12 — Example from mechanical engineering field
6.2.4 Reference indication for cuts and sections
6.2.4.1 General
On large-format technical drawings and technical drawings consisting of more than one drawing sheet
with an extensive amount of cuts and sections, the readability should be improved by information
(reference indication) after the identification letter of the cutting plane and the identification letters of
the referenced cuts and sections.
The purpose is to find the cuts and sections and the identification letters more easily on the technical
drawing or drawings.
6.2.4.2 Details of the reference indication
The reference indication after the identification letter on the views identifies the following:
10 © ISO 2019 – All rights reserved
---------------------- Page: 18 ----------------------
oSIST prEN ISO 128-3:2019
ISO 128-3:2019(E)
• The grid coordinates (Plan square) according to the “ISO 5457 reference grid”.
• The page/ sheet number of multiple-page technical drawings
The full notation shall consist of the items given in Figure 10.
6.2.4.3 Examples of indication
Examples of indication are given in Table 2.
Table 2
Indication on technical drawing Interpretation
Section A-A is represented at technical drawing
coordinates D5
Section B-B is represented at d technical rawing
coordinates F4 on drawing sheet 2
Cutting plane identification A is represented at
technical drawing coordinates C2
Cutting plane identification B is represented at
technical drawing coordinates A8 on drawing
sheet 1.
6.3 Sections revolved in the relevant view
If unambiguous, a section can be revolved in the relevant view. If this is done, the outline of the section
shall be drawn with continuous narrow lines of the type 01.1.16 according to ISO 128-2, Annex F or
01.1.11 according toISO 128-2, Annex D further identification is then not necessary [see Figure 14 a) and
b)].
NOTE The rotational direction of the section in the view is unknown.
© ISO 2019 – All rights reserved 11
---------------------- Page: 19 ----------------------
oSIST prEN ISO 128-3:2019
ISO 128-3:2019(E)
a) Example 1 b) Example 2
Figure 14 — Sections revolved in relevant view
6.4 Cuts/sections of symmetrical parts
Symmetrical parts may be drawn half in view and half in cut/section (see Figure 15).
Figure 15 — Half in section of symmetrical part
6.5 Local cuts/sections
A local cut/section may be drawn if a complete or a half cut/section is unnecessary. The local break shall
be shown by a continuous narrow line with zigzags or freehand of type 01.1.19 or 01.1.18 according to
ISO 128-2, Annex F or 01.1.14 according to ISO 128-2, Annex D. See Figure 16.
Figure 16 — Local cut
12 © ISO 2019 – All rights reserved
---------------------- Page: 20 ----------------------
oSIST prEN ISO 128-3:2019
ISO 128-3:2019(E)
7 Basic conventions for representing areas on cuts and sections
7.1 General information on cuts and sections
There are six methods for the representation of areas on cuts and sections. These consist of indication
— by hatching (see clause 7.2);
— by shading or toning (see clause 7.3);
— by extra-wide continuous outlines (see clause 7.4);
— of thin sections (see clause 7.5);
— of thin adjacent sections (see clause 7.6); and
— of special materials (see clause 7.7).
Allowance shall be made for the means of reproduction used, in accordance with ISO 6428.
7.2 Hatching
Hatching shall be done with parallel narrow continuous lines of type 01.1.5 specified in ISO 128-2,
Annex F and at a convenient angle (preferably 45° to the principal outlines or lines of symmetry of cuts
or sections (see Figure 17).
Figure 17 — Hatching of areas of cuts or sections — Examples
Separate areas of a cut or section of the same component shall be hatched in an identical manner. The
hatching of adjacent components shall be carried out using the specified lines running in different
directions or d
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.